Broadcast program providers usually broadcast schedules of their programs, including at least program titles and start times, but sometimes also additional information like program identifiers that are unique within a certain scope, actor and/or director names, year of production or similar. Also combined schedules including several programs from several providers are known, e.g. an Electronic Program Guide (EPG) service. Further, many A/V devices such as video cassette recorders (VCR), DVD recorders, hard disk drive (HDD) recorders or combinations thereof, offer the possibility to schedule recordings, i.e. to specify at which time a recording shall start.
In today's video and/or DVD recording appliances it is common to extract the programming data for the timer from an integrated Electronic Program Guide (EPG). Devices that provide his feature are e.g. Thomson VPH7090/8090/DTH8000 etc. Generally, the programming data are filtered out of the teletext service or out of special EPG pages according to specified criteria.
It is an experience that very often the same program is broadcasted more than once within a short time range. E.g. an evening program is repeated late at night, or one or few days later. The re-run is often sent on the same channel, but it occurs frequently that a different channel transmits the same program within a short time-frame, or even simultaneously. Moreover, it has been observed that in such cases the programs may have different duration, due to the different duration and amount of commercial interruptions. In general, these cases can be regarded as different instances of the same program, which may differ in matter that is usually not directly connected to the content, such as commercials, banners or other additional data. They must however be distinguished from different episodes of a serial, like e.g. a soap opera, which provide different program content.